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FERRO-VANADIUM

205

TABLE  XVII
Composition of Ferro-tungstens

No.
	W
	Fe
	C
	Si
	Mn
	Al
	Sn
	s    !     p

I
	72-5
	23-29
	i-75
	o-33
	0-80
	0-06
	
	o-oi       o-oi

2
	64-7
	—
	1-36
	o-33
	o-43
	0-09
	Trace
	o-oi       0-007

3
	87-4
	—
	0-38
	0-13
	—
	—
	Trace
	0-07       0-009

4
	70-75
	22-O
	—
	0-3
	0-8
	—
	—
	O-OI          O-O2

5
	83-3
	I5-72
	0-52
	0-13
	~
	• —
	—
	o-oi       o-oi

FERRO -VANADIUM

Ferro-vanadium is obtained exclusively by electro-thermal processes,
or by these in combination with ammino-thermal processes, from mixtures
of ferric oxide and vanadium oxide. They serve as deoxidising agents
in the refining of cast-iron and steels, and for the preparation of vanadium
steels.

As prepared to-day it is comparatively pure and, besides iron and vana-
dium, usually contains only small quantities of carbon and silicon and some-
times traces of phosphorus and manganese. Its analysis includes :

1.  Determination of the Vanadium.—1-2 grams of the sample are
treated in a small porcelain dish with nitric acid (D 1-18), evaporated to
dryness, calcined and the oxides obtained fused with sodium peroxide,
the product being extracted with water as indicated in the analysis of
vanadium steels.1

The liquids from the lixiviation are together made up to 500 c.c. and
the vanadium in an aliquot part determined as with vanadium steel.

2.  Determination of the Carbon and Silicon.—As in ordinary cast-
iron.

3.  Determination of the Phosphorus.—This is carried out on an
aliquot part of the 500 c.c. (see i, above) by the method given for estimating
phosphorus in presence of vanadium (see Iron, 4, 3).

4.  Determination of the Manganese.—As in ferro-silicon.

*
* *

The usual types of ferro-vanadium contain 35-55% of vanadium, with
small quantities of silicon (0-09-1-2%) and carbon (1-3%) and traces of phos-
phorus, sulphur, magnesium and aluminium.

The mean compositions of ferro-vanadiums made in the electric furnace are
as follows (Bonini) :

1 If the sample can be finely powdered, it may be fused at once with a mixture of
sodium carbonate and magnesia (see p. 195), the mass obtained being lixiviated with

water.ganese, phosphorus, etc. ; that from the blast